An MDF board is a medium-density fiberboard. In such a system, the fibers to which glue is to be applied are blown in through a vertical fiber-supply conduit, for example, and a 180° fiber diverter, into a fiber-discharge conduit that is also vertical. Thence the fibers enter into a glue-application zone situated between fiber-discharge conduit and the chute. The glue-coated fibers then drop into the chute, and from there onto the conveyor below the chute. Preferably, an air-jacket supply is furthermore provided, having a line for generating an air jacket that surrounds the fiber stream in the chute, the air jacket and the transport air being drawn off by the suction device, specifically through the foraminous transport belt.
Such a system for applying glue to fibers is known from DE 102 47 412 [WO 2004/035279], DE 102 47 413 [WO 2004/035278], DE 102 47 414 [WO 2004/052603], and DE 10 2004 001 527 [WO 2005/065905]. In the case of the system known from DE 102 47 412, the suction device has a plurality of suction elements, one behind the other in the belt travel direction, i.e. transport direction, in the form of suction registers or suction funnels. The fibers fall through the chute onto the screen belt where they form a fiber mat. Any glue droplets that did not get used also fall through the chute, onto this fiber mat, so that essentially, subsequent glue application occurs. Along the conveyor, a feed mechanism can be provided upstream of the chute that applies fresh fibers to the screen belt, before it passes below the chute. As a result, a preliminary nonwoven fabric essentially forms on the screen belt, so the glue-coated fibers do not land directly on the screen belt, but rather onto the preliminarily formed nonwoven layer. In this manner, contamination of the screen belt with fibers carrying still sticky glue is in theory avoided or reduced. The measures known in this regard have fundamentally proven themselves, but they could be developed further.